How do we know the world has warmed?

The 11 indicators shown below have been compiled by the Met Office Hadley Centre for this purpose. They draw
on the work of over 100 scientists from more than 20 institutions and provide, in one place, a holistic view
of our climate from the depths of the oceans to the high atmosphere. Each indicator is expected to be strongly
correlated with surface temperatures and for each one, multiple analyses are shown. Multiple analyses indicate
which features of the series are not sensitive to the exact choice of analysis method and might be considered
robust features of the climate.

In the long-term, seven of the indicators are rising and four are declining. Each of the indicators is
consistent with the land surface temperature records and shows long-term warming.

The indicators were published in the
BAMS State of the Climate 2009 report.
If you use these images please acknowledge the source as the Met Office Hadley Centre and reference:

The data are provided for documentary purposes only. If you wish to use the data in your analysis please contact
the authors of the papers for the original series. Details are given in each data file. Many are publically
available on the web.

Rising indicators

Air temperature over land

Sea-surface temperature

Marine air temperature

Sea-level

Ocean heat content

Specific Humidity

Tropospheric temperature in the "active-weather" layer of the atmosphere closest to the Earth's surface

Gouretski V. and F. Reseghetti 2010. On depth and temperature biases in bathythermograph data: development of a new correction scheme based on the analysis of global ocean data. Deep Sea Res. submitted.

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